/*
*  Copyright (c) 2001 Sun Microsystems, Inc.  All rights
*  reserved.
*
*  Redistribution and use in source and binary forms, with or without
*  modification, are permitted provided that the following conditions
*  are met:
*
*  1. Redistributions of source code must retain the above copyright
*  notice, this list of conditions and the following disclaimer.
*
*  2. Redistributions in binary form must reproduce the above copyright
*  notice, this list of conditions and the following discalimer in
*  the documentation and/or other materials provided with the
*  distribution.
*
*  3. The end-user documentation included with the redistribution,
*  if any, must include the following acknowledgment:
*  "This product includes software developed by the
*  Sun Microsystems, Inc. for Project JXTA."
*  Alternately, this acknowledgment may appear in the software itself,
*  if and wherever such third-party acknowledgments normally appear.
*
*  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
*  must not be used to endorse or promote products derived from this
*  software without prior written permission. For written
*  permission, please contact Project JXTA at http://www.jxta.org.
*
*  5. Products derived from this software may not be called "JXTA",
*  nor may "JXTA" appear in their name, without prior written
*  permission of Sun.
*
*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
*  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
*  DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
*  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
*  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
*  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
*  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
*  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
*  SUCH DAMAGE.
*  ====================================================================
*
*  This software consists of voluntary contributions made by many
*  individuals on behalf of Project JXTA.  For more
*  information on Project JXTA, please see
*  <http://www.jxta.org/>.
*
*  This license is based on the BSD license adopted by the Apache Foundation.
*
*  $Id: ElizaListener.java,v 1.10 2007/05/23 21:00:17 nano Exp $
*/

package net.jxta.myjxta.dialog.listener;

import net.jxta.myjxta.dialog.Dialog;
import net.jxta.myjxta.dialog.DialogListener;
import net.jxta.myjxta.dialog.DialogMessage;
import net.jxta.myjxta.dialog.DialogMessageWrapper;
import net.jxta.myjxta.dialog.util.Text;
import net.jxta.myjxta.misc.eliza.Eliza;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Random;

/**
 * @author james todd [gonzo at jxta dot org]
 * @author mike mcangus [mcangus at jxta dot org]
 * @version $Id: ElizaListener.java,v 1.10 2007/05/23 21:00:17 nano Exp $
 */

public final class ElizaListener
        implements DialogListener {

    private static final String ENQUE = "hi ";
    private static final String DEQUE = "bye ";
    private static final String HELLO = "Hello ";
    private static final String GOODBYE = "Goodbye ";
    private static final String PERIOD = ".";
    private static final String SPACE = " ";
    private static final String SCRIPT =
            "/net/jxta/myjxta/resources/eliza/eliza.txt";
    private static final int MAX_NO_ELIZA = 20 * 1000 * 3 * 20;
    private static final int SLEEP = 7 * 1000;
    private static final int INTERVAL_BASE = 3 * 1000;
    private static final int INTERVAL = 15 * 1000;

    private final Eliza eliza ;
    private Map<String, Long> cache = null;
    private final Random random ;

    {
        this.eliza = new Eliza();

        this.eliza.readScript(false, getClass().getResource(SCRIPT).toString());

        this.random = new Random();

        Thread t = new Thread(new Runnable() {
            public void run() {
                while (true) {
                    try {
                        Thread.sleep(SLEEP);
                    } catch (InterruptedException ignored) {
                        // ignored
                    }

                    if (cache != null) {
                        long now = System.currentTimeMillis();
                        long l = 0;
                        String k = null;

                        for (Iterator<String> i = cache.keySet().iterator();
                             i.hasNext();) {
                            k = i.next();
                            l = cache.get(k).longValue();

                            if (now - l >= MAX_NO_ELIZA) {
                                cache.remove(k);
                            }
                        }
                    }
                }
            }
        }, getClass().getName() + ":reap");

        t.setDaemon(true);

        t.start();
    }

    public void receive(DialogMessage msg) {
        DialogMessageWrapper dw = (DialogMessageWrapper) msg;
        String s = msg != null ? msg.getPlainTextMessage() : null;
        String o = msg != null ? msg.getOriginator() : null;
        String me = dw.getDialog().getGroup().getPeerGroup().getPeerName();

        s = s != null ?
                Text.replace(s.trim(), Text.MARKUP, Text.EMPTY) : null;
        o = o != null ? o.trim() : null;

        String enque = ENQUE + me;
        String deque = DEQUE + me;

        if (s != null &&
                s.length() > 0 &&
                o != null &&
                o.length() > 0) {
            boolean connected = this.cache != null &&
                    this.cache.containsKey(o);

            if (!connected &&
                    s.toLowerCase().indexOf(enque.toLowerCase()) > -1 &&
                    !o.equalsIgnoreCase(me)) {
                enque(o);
                enquire(dw.getDialog(), o,
                        HELLO + o + PERIOD + SPACE + this.eliza.processInput(s));
            } else if (connected &&
                    s.toLowerCase().indexOf(deque) > -1) {
                deque(o);
                enquire(dw.getDialog(), o, GOODBYE + o + PERIOD);
            } else if (connected) {
                enque(o);
                enquire(dw.getDialog(), o, this.eliza.processInput(s));
            }
        }
    }

    private void enque(String o) {
        if (this.cache == null) {
            this.cache = new HashMap<String, Long>();
        }

        this.cache.put(o, now());
    }

    private void deque(String o) {
        if (this.cache != null &&
                this.cache.containsKey(o)) {
            this.cache.remove(o);

            if (this.cache.size() == 0) {
                this.cache.clear();
                this.cache = null;
            }
        }
    }

    private void enquire(final Dialog dialog, final String originator,
                         String enquire) {
        if (this.eliza.finished()) {
            deque(originator);
            this.eliza.setFinished(false);
        }

        final String s = enquire;

        if (originator != null &&
                originator.trim().length() > 0 &&
                enquire != null &&
                enquire.trim().length() > 0) {
            final int sleep = INTERVAL_BASE +
                    (int) (INTERVAL * this.random.nextFloat());

            Thread thread = new Thread(new Runnable() {
                public void run() {
                    try {
                        Thread.sleep(sleep);
                    } catch (InterruptedException ignored) {
                        // ignored
                    }

                    dialog.dispatch(s);
                }
            }, getClass().getName() + ":enquire");
            thread.setDaemon(true);
            thread.start();
        }
    }

    private Long now() {
        return new Long(System.currentTimeMillis());
    }
}
